Evolutions of composition, microstructure and optical properties of Mn-doped pyrite (FeS2) films prepared by chemical bath deposition

A series of Mn-doped pyrite (FeS2) films with different Mn/Fe ratios were synthesized by chemical bath deposition process and the followed sulfurization treatment. The effects of Mn contents on the grain morphology, structural and optical properties of the synthesized films were studied via EDS, XRD, Raman spectroscopy, SEM and ultraviolet–visible light spectroscopy. Results showed that the FeS2 films showed (2 0 0) preferred orientation after doping Mn element. Films with special light-trapping network were obtained by increasing doping content, as a result of the (2 0 0) preferred orientation plane of Fe1−xMnxO2 films. It was confirmed that the raising of absorption coefficients of the films from 2.0 × 105 cm−1 to 3.7 × 105 cm−1 was mainly attributed to the special microstructure and the band-gap energy Eg of thin films were also modified to 1.31 eV.